A POAS threshold is the simplest piece of automation you will set, and it pays for itself the fastest. The hard part is picking a number that is defensible, not arbitrary, and operating it in a way that builds trust before you let it touch live spend.
Pick a defensible floor
The most common mistake is to start at break-even POAS (1.0). Break-even sounds principled but it is a thermometer, not a floor — and the floor is what triggers the action.
Use the median POAS of your top-decile campaigns as a starting reference and pick a floor at roughly 70% of that. For most Shopify operators this lands between 1.4 and 1.9. It is high enough to catch the bleed and low enough to avoid false positives in the first week.
Operate notify-only first
Notify-only sends you a daily list of campaigns currently below the floor. No spend is paused. The point of week one is calibration, not action — you want to see whether the list is dominated by genuinely losing campaigns or by transient noise (a single bad day, a new launch ramping, a promo overlap).
After a week, you will have a feel for how the list moves. If it is stable and the campaigns on it are the ones you would have paused anyway, you are ready to promote.
Promote to auto-exclude, then to auto-pause
The promotion path is deliberate. Auto-exclude removes a placement or audience from a campaign without touching the campaign’s budget. Auto-pause stops the campaign entirely.
- Auto-exclude is reversible in one click and rarely produces buyer’s remorse — promote here first.
- Auto-pause should only kick in after the floor has been stable for at least two weeks and you have a written rule for which kinds of campaigns are eligible (e.g. mature campaigns above a minimum spend, not launches).
- Keep notify-only as the floor of the floor — there is always a tier of activity for which you only ever want to be told.
Tune the floor monthly, not weekly
POAS distributions drift as your mix changes, as competitors move, and as you change pricing. A monthly tune of the floor — based on the median of your top decile — keeps the threshold honest. Tuning weekly overfits to noise and will eventually mute the system.
- Set the floor at ~70% of your top-decile median POAS, not at break-even.
- Operate notify-only for the first week to calibrate.
- Promote in order: auto-exclude first, auto-pause second, with notify-only always retained for sensitive activity.